Some problem on cross compile may be, that the gcc on your host has different configuration than on your odroid.
means different search path

type
g++ -E -x c++ - -v < /dev/null

on both machines, your host and on your odroid
then compare the lines starting from

#include "..." search starts here:
#include <...> search starts here:

you'll notice they are diferent
and there is the problem

what you can do is

cd to [qtsrc]/qtbase/mkspecs/devices/
to let the original untouched
make a copy of
linux-odroid-xu3-g++/
example:
cp -R linux-odroid-xu3-g++ my_linux-odroid-xu3-g++
cd into my_linux-odroid-xu3-g++
and with your favorit editor and open qmake.conf
add the lines you got from "g++ -E -x c++ - -v < /dev/null" on your odroid as include and libs

example:
if you got a line like
/usr/include/arm-linux-gnueabihf/c++/4.8